This prospective cohort study will provide estimates of the relative and attributable risks of different induced abortion experiences and procedures for a number of complications of subsequent pregnancies, labor, deliveries and newborns. All women (estimated n equals 8,000) who have made a first prenatal visit to physicians, health plans and clinics, and who anticipate delivery at Yale-New Haven Hospital, will be invited to participate in the study. To ascertain information about abortion experiences and other risk factors patients will be interviewed, with their physicians's consent, using a standardized questionnaire given by trained interviewers. Supplemental information will be obtained from physicians and clinics where abortion was obtained. Information about pregnancy outcomes will be obtained by surveying all deliveries at the hospital and linking these to respondents who have been interviewed. Obstetricians and patients may be recontacted if necessary. In the analysis complications of pregnancy, labor, delivery and in newborns will be compared in women exposed and not exposed to prior abortion. Experience of abortion will include: number and sequence of abortions, technique used and gestation at abortion. Possible confounding factors will be accounted for such as: maternal age, pregnancy history, smoking history, history of venereal infections, interpregnancy intervals and contraceptive use. A multivariate analysis using log liner models will be used which can identify sub-groups of women who have unusually high or low risk of developing complications if exposed to induced abortion.